JPH11222100A - Seat belt retractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb kinetic energy of an occupant at vehicle emergency time, surely restrain the occupant finally by webbing, in a seat belt retractor provided with a spindle functioning as a torsion bar. SOLUTION: In a seat belt retractor 1, a tightening mechanism 8 is provided, which permits torsion deformation of a spindle 4 tilt leading to a prescribed value of torsional deformation rotational amount on a part in the vicinity of a right end in a left end part of the spindle 4 at vehicle emergency time and, when the torsional deformation rotational amount leads to the prescribed value, tightens the right end vicinity part of the spindle 4 and a winding drum 3 incapable of relatively rotation, this constitution is formed such that kinetic energy of an occupant is adsorbed at vehicle emergency time, and in the final end, the occupant is surely restrained by webbing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt retractor, and more particularly, to absorbing energy applied to an occupant by torsional deformation of a spindle shaft functioning as a torsion bar in a vehicle emergency, and finally, occupant by webbing. The present invention relates to a seat belt retractor that is securely restrained.

[0002]

2. Description of the Related Art Conventionally, in a seat belt retractor mounted on an automobile, in the event of a vehicle emergency due to a vehicle collision or the like, an emergency lock mechanism locks a take-up drum so that it cannot rotate in a webbing pull-out direction. The webbing is prevented from being pulled out.

[0003] In a vehicle emergency, if the deceleration of the vehicle becomes very large, the load received by the occupant from the webbing becomes very large, which is not desirable. Therefore, in recent seat belt retractors, when the rotation of the winding drum is substantially locked by the emergency lock mechanism and the load acting on the webbing increases, the energy is absorbed by the energy absorbing means while allowing the rotation of the winding drum. Absorb,
The impact acting on the occupant is reduced.

For example, Japanese Patent Application Laid-Open Nos. 7-277136 and 7-101310 disclose a seat belt retractor in which a deformable member as the energy absorbing means is mounted along an outer peripheral surface of a winding drum. I have.
In this seat belt retractor, in the event of a vehicle emergency, the take-up drum is locked by the emergency lock mechanism so that it cannot rotate, and when a large load acts on the webbing, the deformable member deforms in the diameter reducing direction and energy is absorbed through the deformation. It has become so. However, this type of seat belt retractor has a complicated structure and is difficult to assemble.

On the other hand, Japanese Patent Application Laid-Open No. Hei 6-156888 discloses a seat belt retractor to which a torsion bar (torsion bar) as the energy absorbing means is applied. In this seat belt retractor, the torsion bar is inserted into the take-up drum, and one end of the torsion bar is connected to the take-up drum so as not to rotate relatively.

A head portion is formed at the other end of the torsion bar, and when a predetermined load (for example, 4 KN) acts on the webbing in a state where the head portion is locked by an emergency lock mechanism in a vehicle emergency and cannot rotate. One end of the torsion bar rotates together with the winding drum, so that the torsion bar is torsionally deformed, and energy is absorbed through the torsionally deformed. The seatbelt retractor to which the torsion bar is applied is excellent in that the structure is simple and the assembly is easy, the energy absorption performance is stable and the reliability is high.

[0007]

Problems to be Solved by the Invention
In the seat belt retractor disclosed in Japanese Patent No. 156884, in the event of a vehicle emergency, the emergency lock mechanism only locks the head of the torsion bar, and does not lock one end of the torsion bar. Even if it acts, the rotation of the winding drum is not restricted, and the torsion bar continues torsional deformation,
There is a possibility that the webbing feeding amount exceeds the limit value, or the torsion bar is broken and the body restraining function is lost. In particular, when a torsion bar is repeatedly torsionally deformed, for example, when a vehicle collides with a ball, the torsion bar is easily broken.

An object of the present invention is to provide a seat belt retractor having a spindle shaft functioning as a torsion bar, to absorb the kinetic energy of the occupant in the event of a vehicle emergency and to surely restrain the occupant by webbing. And so on.

[0009]

A seat belt retractor according to claim 1, wherein a winding drum for winding the webbing;
A seat belt retractor having an end portion engaged with the winding drum so as to be relatively non-rotatable and functioning as a torsion bar, and absorbing energy by torsional deformation of the spindle shaft in a vehicle emergency. Sometimes, the torsional deformation of the spindle shaft is allowed until the torsional deformation rotation amount of one end of the spindle shaft with respect to the other end vicinity becomes a predetermined value, and when the torsional deformation rotation amount reaches the predetermined value, the spindle is rotated. It is characterized in that a fastening mechanism is provided for fastening the vicinity of the other end of the shaft and the winding drum so that they cannot rotate relative to each other.

The predetermined value of the torsional deformation rotation amount is a value at which the spindle shaft does not break, and is set to a value at which the occupant does not reach the steering wheel or the like due to the feeding of the webbing due to the torsional deformation of the spindle shaft. . The load acting on the occupant from the webbing when the spindle shaft is torsionally deformed can be appropriately set by appropriately designing the shape, material, and the like of the spindle shaft.

Since one end of the spindle shaft is engaged with the take-up drum so as not to rotate relatively, the rotation of the other end of the spindle shaft is locked by some kind of emergency locking means in the event of a vehicle emergency. When a large load is applied, the winding drum rotates together with one end of the spindle shaft, and the spindle shaft is torsionally deformed, and energy is absorbed through the torsional deformation. afterwards,
When the torsional deformation rotation amount reaches a predetermined value, the vicinity of the other end of the spindle shaft and the winding drum are fastened by the fastening mechanism so that the winding drum cannot rotate relative to each other, and the winding drum stops rotating. Of the webbing is prevented, and the occupant is securely restrained by the webbing.

Therefore, even when a very large load is applied to the webbing in the event of a vehicle emergency, or when the spindle is repeatedly torsionally deformed due to collision of the vehicle a plurality of times, the kinetic energy of the occupant is absorbed and the spindle shaft is absorbed. As a result, the occupant can be reliably restrained by the webbing, so that a secondary collision of the occupant with the steering wheel, the front window, etc. is reliably prevented, and the safety of the occupant is ensured. be able to.

According to a second aspect of the present invention, there is provided a seat belt retractor configured to absorb energy through torsional deformation of a torsion bar in a vehicle emergency, and a winding drum for winding webbing, and a winding drum for winding the webbing. A spindle shaft having a torsion bar portion, one end of which is non-rotatably engaged with the take-up drum, and an emergency which locks the vicinity of the other end of the spindle shaft non-rotatably in a vehicle emergency. The take-up drum and one end of the spindle shaft are integrally rotated by the tension applied to the webbing after the locking means and the emergency locking means are operated, and the one end of the spindle shaft is twisted in the webbing pull-out direction with respect to the vicinity of the other end of the spindle shaft. The torsional deformation of the spindle shaft until the torsional deformation rotation amount reaches a predetermined value, and the torsional deformation rotation amount is a predetermined value. Reached and is characterized in that a fastening mechanism for fastening the other end part near the winding drum of the spindle shaft in a relatively non-rotatable manner when the.

The predetermined value of the amount of rotation of the torsional deformation is a value at which the spindle shaft is not broken, as in the first embodiment, and the occupant can move the steering wheel or the like by feeding out the webbing due to the torsional deformation of the spindle shaft. Is set to a value that does not reach. Further, the load acting on the occupant from the webbing when the spindle shaft is torsionally deformed is also the same as in the first aspect.

In a vehicle emergency, the vicinity of the other end of the spindle shaft is locked non-rotatably by the emergency locking means, and when a large load of, for example, 4 KN or more acts on the webbing, the winding drum rotates together with one end of the spindle shaft. The torsion bar portion of the spindle shaft is torsionally deformed, and energy is absorbed through the torsionally deformed portion. Thereafter, when the torsional deformation rotation amount reaches a predetermined value, the vicinity of the other end of the spindle shaft and the take-up drum are fastened by the fastening mechanism such that the take-up drum does not rotate. The feeding of the webbing from the take-up drum is prevented, and the occupant is securely restrained by the webbing. Other functions are the same as those of the first aspect.

According to a third aspect of the present invention, there is provided the seat belt retractor according to the first or second aspect of the present invention, wherein the fastening mechanism is formed in the vicinity of the other end of the spindle shaft and the female screw formed in one of the winding drums and the other. And a male screw part having a male screw part screwed to the female screw part.

Therefore, in the event of a vehicle emergency, the winding drum can be relatively rotated with respect to the vicinity of the other end of the spindle shaft until the rotation amount of the torsional deformation of the spindle shaft reaches a predetermined value. When the torsional deformation rotation amount reaches a predetermined value, the female screw and the male screw of the screwing mechanism are screwed and fastened to connect the vicinity of the other end of the spindle shaft and the winding drum. It can be fastened so that relative rotation is impossible.
Other operations are the same as those of the first or second aspect.

According to a fourth aspect of the present invention, in the seat belt retractor according to the first or second aspect of the present invention, the fastening mechanism constitutes a part of an emergency locking means for locking the vicinity of the other end of the spindle shaft in a non-rotatable manner in a vehicle emergency. And a screwing mechanism having a female screw portion formed on one of the ratchet wheel and the winding drum and a male screw portion formed on the other and screwed to the female screw portion.

Therefore, in the event of a vehicle emergency, the winding drum is allowed to rotate relative to the ratchet wheel until the torsional deformation rotation amount of the spindle shaft reaches a predetermined value, thereby allowing the torsional deformation of the spindle shaft. When the torsional deformation rotation amount reaches a predetermined value, the female screw and the male screw of the screwing mechanism are screwed and fastened, and the other end near the spindle shaft and the winding drum are connected via the ratchet wheel. It can be fastened so that relative rotation is impossible. Other operations are the same as those of the first or second aspect.

According to a fifth aspect of the present invention, there is provided the seat belt retractor according to the third aspect of the present invention, wherein the fastening mechanism contacts the vicinity of the other end of the spindle shaft with the winding drum by bringing the vicinity of the other end of the spindle shaft into contact with the winding drum. It is characterized by fastening with a winding drum. Therefore, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the vicinity of the other end of the spindle shaft and the winding drum come into contact, and the vicinity of the other end of the spindle shaft and the winding drum come into contact with each other. Fastened securely.
Other effects are the same as those of the third aspect.

According to a sixth aspect of the present invention, in the invention of the fourth aspect, the fastening mechanism causes the ratchet wheel and the winding drum to abut on each other, thereby connecting the vicinity of the other end of the spindle shaft to the winding drum. It is characterized by fastening. Therefore, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ratchet wheel and the winding drum come into contact with each other, and the vicinity of the other end of the spindle shaft and the winding drum are connected via the ratchet wheel. Fastened securely. Other operations are the same as those of the fourth aspect.

According to a seventh aspect of the present invention, in the seat belt retractor according to the first or second aspect, the fastening mechanism is externally screwed to a portion near the other end of the spindle shaft and internally fitted to the winding drum so as to be relatively non-rotatable. A ring member provided.

Therefore, in the event of a vehicle emergency, the ring member and the ring member can be rotated relative to the spindle shaft together with the winding drum until the amount of rotation of the spindle shaft becomes a predetermined value. When the torsional deformation rotation amount reaches a predetermined value, the ring member is screwed and fastened to the vicinity of the other end of the spindle shaft, and wound around the other end of the spindle shaft via the ring member. It can be fastened to the drum so that it cannot rotate relatively. Other operations are the same as those of the first or second aspect.

According to an eighth aspect of the present invention, in the first or second aspect of the present invention, the fastening mechanism constitutes a part of an emergency locking means for locking the vicinity of the other end of the spindle shaft in a non-rotatable manner in a vehicle emergency. And a ring member which is externally screwed to the ratchet wheel and is internally fitted to the winding drum so as to be relatively non-rotatable.

Therefore, in the event of a vehicle emergency, the ring member and the ring member can be rotated relative to the ratchet wheel until the torsional deformation rotation amount of the spindle shaft reaches a predetermined value. When the torsional deformation rotation amount reaches a predetermined value, the ring member is screwed and fastened to the ratchet wheel, and the other end portion of the spindle shaft and the winding drum are connected via the ring member and the ratchet wheel. And can be fastened so that they cannot rotate relative to each other. Other operations are the same as those of the first or second aspect.

According to a ninth aspect of the present invention, in the seat belt retractor according to the seventh or eighth aspect, the ring member is fitted inside the winding drum so as to be relatively movable in the axial direction thereof. Things. Therefore, when the ring member is relatively rotated with respect to the spindle shaft or the ratchet wheel, the movement of the ring member in the axial direction can be allowed, and expansion and contraction due to torsional deformation of the spindle shaft can be allowed. Other effects are the same as those of the seventh or eighth aspect.

[0027] The seat belt retractor of claim 10 is
The invention according to claim 7, wherein the fastening mechanism fastens the winding drum to the vicinity of the other end of the spindle shaft by bringing the ring member into contact with the winding drum. Therefore, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ring member and the winding drum come into contact with each other, and the vicinity of the other end of the spindle shaft and the winding drum via the ring member. Fastened securely. Other effects are the same as those of the seventh aspect.

The seat belt retractor according to claim 11 is
The invention according to claim 8 is characterized in that the fastening mechanism fastens the winding drum to the vicinity of the other end of the spindle shaft by bringing the ring member into contact with the ratchet wheel. Therefore, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ring member and the ratchet wheel come into contact with each other, and are wound around the other end portion of the spindle shaft via the ring member and the ratchet wheel. The drum is securely fastened. Other effects are the same as those of the eighth aspect.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to a seatbelt retractor that absorbs energy through torsional deformation of a spindle shaft that functions as a torsion bar in a vehicle emergency such as a vehicle collision. Note that the front, rear, left and right in FIG.

As shown in FIGS. 1 to 3, a seat belt retractor 1 includes a metal housing 2 fixed to a vehicle body, a winding drum 3 mounted on the housing 2 and winding a webbing W, and a winding drum 3. A spindle shaft 4 disposed so as to be inserted into the drum 3 and having a left end portion engaged with the winding drum 3 so as to be relatively non-rotatable; and a rotating shaft for constantly biasing the winding drum 3 in the winding direction. Force mechanism 5, a forced winding mechanism 6 for forcibly rotating the winding drum 3 in the winding direction in the event of a vehicle emergency such as a vehicle collision and winding the webbing W, and a portion near the right end of the spindle shaft 4 in the event of a vehicle emergency. An emergency lock mechanism 7 that locks the spindle shaft 4 so that the spindle shaft 4 cannot rotate so as to allow the spindle shaft 4 to torsionally deform until the rotation amount of the left end portion of the spindle shaft 4 near the right end thereof reaches a predetermined value in the event of a vehicle emergency, and The torsional deformation rotation There has been a fastening mechanism 8 for fastening the right end part near the winding drum 3 of the spindle shaft 4 to rotate relative when it reaches a predetermined value.

As shown in FIGS. 1-3, the housing 2
A left wall 10, a right wall 11, a rear wall 12 connecting the left upper wall 10 and the right rear wall 11 with a rear upper end, a connecting plate 13 connecting the left wall 10 and the right rear wall 11 with a lower rear part thereof, The mounting plate 13a fixed to the rear wall portion 12 and the connecting plate portion 13 and extending downward is fixed to the vehicle body with bolts or the like.
The front upper ends of the left side wall 10 and the right side wall 11 are connected by a bar member 14 oriented in the left-right direction.

Circular openings 15 and 16 having a smaller diameter than the winding drum 3 are formed concentrically on the left side wall 10 and the right side wall 11, and a pawl 60 of the emergency lock mechanism 7 is formed on the lower right side of the right side wall 11. The holder 67 is mounted. Rear wall 12
A rectangular opening 17 is formed between the connecting plate 13 and the
Although not shown, when most of the webbing W is wound on the winding drum 3, the rear end portion of the webbing W having a larger diameter reaches the inside of the opening 17 so as not to interfere with the housing 2.

As shown in FIGS. 1 to 3 and FIGS. 5 to 7, the winding drum 3 has a body portion 20 around which the webbing W is wound around the outer peripheral portion, a left flange portion 21, and a right flange portion 22. And an insertion hole 23 in the left-right direction through which the spindle shaft 4 is inserted is formed in the axial center portion. A spline hole 24 is formed in the left flange 21, and an insertion hole 25 communicating with the insertion hole 23 and the spline hole 24 and having a diameter larger than the insertion hole 23 is formed in the left end portion of the winding drum 3. Have been.

The right flange 22 is formed wide in the right and left direction, and a spline-shaped fitting hole 26 communicating with the insertion hole 23 and having a diameter larger than that of the insertion hole 23 is formed in a central portion thereof. The ring member 70 of the fastening mechanism 8 is fitted in the hole 26 so as to be relatively non-rotatable and relatively movable left and right. Also,
A webbing insertion opening 27 for fitting and fixing the base end of the webbing W is formed in the body portion 20.

As shown in FIG. 1 and FIGS. 4 to 7, the spindle shaft 4 has a torsion bar portion 30 that is torsionally deformed when a predetermined or more torsion torque acts, and a torsion bar portion 3.
0, a knurled shaft portion 31 on the left end side, a spline shaft portion 32 on the right end side of the torsion bar portion 30, and a connection shaft portion 33 on the right end side of the spline shaft portion 32, which are integrally formed. 31 is non-rotatably engaged with the left end of the winding drum 3 via the cap member 35,
The ratchet wheel 50 of the emergency lock mechanism 7 is connected to the spline shaft portion 32 so as not to rotate relatively.

The cap member 35 has a spline-shaped engaging portion 36, a cylindrical portion 37 extending rightward from the engaging portion 36, and a knurled hole 38 formed inside the cylindrical portion 37. The mating portion 36 is engaged with the spline hole 24 of the winding drum 3, the cylindrical portion 37 is inserted into the insertion hole 25, and the knurled shaft portion 31 of the spindle shaft 4 is inserted into the knurled hole portion 38.
Are engaged. The cap member 35 is integrally formed with a connection shaft portion 39 having a square cross section extending leftward from the engagement portion 36, and the connection shaft portion 39 is operable by the forcible winding mechanism 6 and the rotation urging mechanism 5. It is connected to.

Although not shown, the cylindrical portion at the base end of the webbing W is externally fitted to the torsion bar portion 30 of the spindle shaft 4, and the webbing W is moved from the torsion bar portion 30 to the winding drum 3. Webbing insertion opening 2 of body 20
7 and is wound around the body 20.

As shown in FIGS. 1 to 3, the rotation urging mechanism 5
Is a mainspring (not shown) accommodated in a spring accommodating cap 40 fixed to the casing 41 of the forcible winding mechanism 6 and has a mainspring for urging the connecting shaft portion 39 in the winding direction. The take-off mechanism 6 includes a gas generator 43 that generates pressurized gas in the event of a vehicle emergency, and a casing 41.
And a gas pressure drive mechanism (not shown) for rotating the winding drum 3 in the winding direction via the cap member 35 by the gas pressure generated by the gas generator 43. still,
Since the rotation urging mechanism 5 and the forced winding mechanism 6 are well-known, detailed description thereof will be omitted.

The emergency lock mechanism 7 will be described.
As shown in FIGS. 1 to 4, the emergency lock mechanism 7 includes a ratchet wheel 50 connected to the spline shaft portion 32 of the spindle shaft 4 so as to be relatively non-rotatable, and a ratchet wheel 50 in response to a sudden withdrawal of the webbing W. And a second lock mechanism that locks the rotation of the ratchet wheel 50 in response to sudden deceleration in the event of a vehicle emergency. The emergency lock mechanism 7 is covered by a cover member 7a fixed to the right side wall 11 of the housing 2.

As shown in FIGS. 4 and 5, the ratchet wheel 50 includes a gear portion 53 having a ratchet gear 54 formed on the outer peripheral portion, and a gear portion 53 having a smaller diameter than the gear portion 53.
And a cylindrical portion 56 having a smaller diameter than the guide portion 55 and extending leftward from the guide portion 55, and is formed integrally with the gear portion 53 and the spline formed on the guide portion 55. The spline shaft portion 32 of the spindle shaft 4 is engaged with the hole 58. The gear portion 53 is disposed on the right side of the right side wall 11 of the housing 2, and the guide portion 55
A ring-shaped synthetic resin bearing ring 57 is rotatably supported on the peripheral surface of the circular opening 16 formed in the right side wall 11, and a ring member 70 is externally fitted to the cylindrical portion 56.

The first lock mechanism includes a pawl 60 rotatably supported by a shaft 19 fixed to the right side wall 11 of the housing 2 and engageable with the ratchet gear 54, and a connecting shaft of the spindle shaft 4. A clutch member 62 formed with a guide portion 62a pivotally supported by the shaft 33 and guiding the pawl 60 with respect to the ratchet gear 54 in an engagement / disengagement direction; and a cylindrical portion 62b of the clutch member 62 connected to the connection shaft portion 33 A lock arm base 66 accommodated in the clutch member 62 and a cylindrical portion 6 of the clutch member 62 supported to be swingable by the lock arm base 66.
Projection 64 that engages with internal teeth 62c formed inside 2b
a is formed and normally the projection 64a is
, A locking gear 65 pivotally supported by the connecting shaft 33 and prevented from being removed by the rivet 61, and a lock abutting on the lock arm 64 and frictionally coupled to the locking gear 65. It is composed of an arm guide (not shown) and the like.

In the normal state, the pawl 60 is rotationally urged by the torsion spring 63 to a disengaged position where the pawl 60 is not engaged with the ratchet gear 54, and when the webbing W is pulled out suddenly and the connecting shaft 33 rotates. , The rotation of the locking gear 65 is delayed with respect to the lock arm base 66, and the rotation of the lock arm guide is also delayed.
4 rotates against the spring force, and the protrusion 64 a
c. Then, the clutch member 62 rotates, and is guided by the guide portion 62a of the clutch member 62 so that the pawl 6
0 rotates against the urging force of the torsion spring 63 and engages with the ratchet gear 54, so that the rotation of the spline shaft portion 32 of the spindle shaft 4 together with the ratchet wheel 50 is locked.

The second lock mechanism is pivotally supported by the connecting shaft 33 on the right side of the pawl 60, the clutch member 62, the lock arm base 66, the lock arm 64, and the lock arm 64, and is disengaged by the rivet 61. The locking gear 65 stopped, the holder 67 fixed to the right side wall 10 of the housing 2, the spherical inertial mass 68 housed in the holder 67, and the rocking gear 65 which is swingably connected to the holder 67 and is connected to the locking gear 65. It has a swing lever 69 that can be engaged.

In a normal state, the locking gear 65 rotates integrally with the connecting shaft 33 of the spindle shaft 4 via frictional force, and when the vehicle suddenly decelerates, the inertial mass body 68 accommodated in the holder 67 is moved. Then, the swing lever 69 swings to engage with the locking gear 65, and the locking gear 6
5 is locked. Then, the locking gear 65
The relative rotation of the lock arm 64 with respect to the lock arm guide causes the projection 64a to engage with the internal teeth 62c and rotate the clutch member 62, and the rotation of the spline shaft portion 32 of the spindle shaft 4 together with the ratchet wheel 50 as described above. Locked.

The fastening mechanism 8 will be described. Figure 1,
As shown in FIGS. 5 and 7 to 9, the fastening mechanism 8 is externally fitted via a screwing mechanism 75 to a cylindrical portion 56 of the ratchet wheel 50 which is connected to the spline shaft portion 32 of the spindle shaft 4 so as to be relatively non-rotatable. It has a threaded ring member 70. The ring member 70 is fitted in the fitting hole 26 of the winding drum 3 and is provided so as not to rotate relative to the winding drum 3 and to be relatively movable in the axial direction (left-right direction).

The screwing mechanism 75 includes a female screw portion 76 formed on the inner periphery of the ring member 70 and the ratchet wheel 5.
A male screw portion 77 formed on the outer periphery of the cylindrical portion 56 and screwed to the female screw portion 76. The male screw portion 77 of the cylindrical portion 56 and the female screw portion 76 of the ring member 70 are formed into a positive screw, and a ring is formed. When the member 70 rotates in the direction indicated by the arrow A in FIG. 7 with respect to the cylindrical portion 56, the member 70 moves rightward as indicated by the arrow B in FIGS. 5 and 8, and as shown in FIG. The right end surface contacts the left end surface of the guide portion 55 of the ratchet wheel 50, and the ring member 70 and the cylindrical portion 56 are integrated so that relative rotation is impossible.

In the fastening mechanism 8, in the event of a vehicle emergency, the amount of torsional deformation rotation of the knurled shaft portion 31 of the spindle shaft 4 with respect to the spline shaft portion 32 becomes a predetermined value at which the ring member 70 cannot be rotated. Spindle shaft 4
The torsion bar portion 30 is allowed to torsionally deform, and when the torsion deformation rotation amount reaches a predetermined value, the spindle shaft 4
The spline shaft portion 32 and the take-up drum 3 are fastened via a ring member 70 and a ratchet wheel 50 so that they cannot rotate relative to each other.

Here, the number of rotations at which the ring member 70 can rotate relative to the cylindrical portion 56 before the right end surface of the ring member 70 contacts the left end surface of the guide portion 55, that is, the amount of torsional deformation rotation is: When assembling the ring member 70, the ring member 70
Can be easily set by rotating the retractor member 70 by a desired number of rotations in a direction opposite to the above from a state where the right end surface of the guide member 55 is in contact with the left end surface of the guide portion 55. In this case, it is desirable to apply a resin coating to the cylindrical portion 56 so as to prevent the ring member 70 from easily rotating, and to apply a frictional force between the cylindrical portion 56 and the ring member 70 to some extent.

Next, the operation of the seat belt retractor 1 will be described with reference to the load characteristics acting on the webbing W in FIG. In the normal state, since the emergency lock mechanism 7 does not operate, the webbing W can be freely pulled out from the winding drum 3 and set on the waist or chest of the occupant sitting on the seat.

With the webbing W set on the occupant's body, in the event of a vehicle emergency such as a vehicle collision, the winding drum 3 is forcibly rotated in the winding direction by the forced winding mechanism 6, and the slack webbing W is loosened. Is wound around the winding drum 3 and tightened, and the emergency lock mechanism 7
The spline shaft portion 32 of the spindle shaft 4 is locked so as not to rotate. Thereafter, the webbing W wound around the winding drum 3 is tightened, and then the webbing W is unwound and the load acting on the webbing W increases. I will do it.

Thereafter, when the feeding amount of the webbing W reaches L1 and the load acting on the webbing W reaches a predetermined W1, the torsion bar portion 30 of the spindle shaft 4 is torsionally deformed, and the spindle shaft 4 is locked. The knurled shaft portion 31 rotates together with the winding drum 3 with respect to the spline shaft portion 32, the kinetic energy of the occupant is absorbed through the torsion deformation of the torsion bar portion 30, and the load acting on the occupant from the webbing W is reduced. The webbing W is fed out while gradually increasing from W1. At this time, the ring member 70 that rotates together with the winding drum 3 moves rightward through the state of FIG.

Normally, all the kinetic energy is absorbed until the webbing feeding amount reaches L2. However, if the load acting on the webbing W becomes W2 and the amount of torsional deformation rotation of the torsion bar portion 30 of the spindle shaft 4 reaches a predetermined value, as shown in FIG. Surface comes into contact with the left end surface of the guide portion 55,
The ring member 70 is integrated with the ratchet wheel 50,
The spline shaft portion 32 is fastened to the winding drum 3 via the ratchet wheel 50 and the ring member 70 so as not to rotate relatively, thereby preventing the torsion bar portion 30 from breaking. In this way, the take-up drum 3 is completely restrained from rotating, the feeding of the webbing W is prevented, and the occupant is reliably restrained by the webbing W.

As described above, according to the seat belt retractor 1, since the fastening mechanism 8 is provided, after the emergency lock mechanism 7 is operated, the knurled shaft portion 31 of the spindle shaft 4 moves in the webbing withdrawing direction with respect to the spline shaft portion 32. The torsion bar 3 until the torsional deformation rotation amount reaches a predetermined value.
When the amount of rotation of the torsion deformation reaches a predetermined value, the spline shaft portion 32 of the spindle shaft 4 and the winding drum 3 can be fastened to each other so that they cannot rotate relative to each other.

As a result, even when a large load is applied to the webbing W in the event of a vehicle emergency, or when the vehicle is hit several times at a time and the spindle shaft 4 is repeatedly torsionally deformed, the kinetic energy of the occupant is absorbed and Since the spindle shaft 4 is reliably prevented from being broken, and finally the occupant can be reliably restrained by the webbing W, the occupant is reliably prevented from secondary collision with the steering wheel, the front window, etc. Safety can be ensured. The loads W1 and W2 can be appropriately set by appropriately designing the length, diameter, material, allowable value of the torsional deformation rotation amount (the predetermined value), and the like. .

Further, the fastening mechanism 8 is externally screwed into the cylindrical portion 56 of the ratchet wheel 50 engaged with the spline shaft portion 32 of the spindle shaft 3 so as to be relatively non-rotatable, and is not rotatable relative to the winding drum 3. Since the inner member is provided with the ring member 70, the above operation can be reliably realized by a simple structure, and the ring member 70 can be relatively moved in the axial direction with respect to the winding drum 3. Since the ring member 70 is internally fitted, when the ring member 70 relatively rotates with respect to the ratchet wheel 50, the rightward movement of the ring member 70 is allowed, and the expansion and contraction due to the torsional deformation of the spindle shaft 4 is also allowed.

Further, the fastening mechanism 8 fastens the spline shaft portion 32 of the spindle shaft 4 to the winding drum 3 by bringing the ring member 70 into contact with the ratchet wheel 50. When the rotation amount reaches a predetermined value, the ring member 70 and the ratchet wheel 5
0, so that the spline shaft portion 32 of the spindle shaft and the winding drum 3 can be more securely fastened via the ring member 70 and the ratchet wheel 50.

In the fastening mechanism 8 of the seat belt retractor 1, the cylindrical portion 56 of the ratchet wheel 50
When the threaded portion of the ring member 70 is formed into a reverse thread, and the ring member 70 rotates in the direction indicated by the arrow A in FIG. 7 with respect to the cylindrical portion 56, the ring member 70 is moved to the left, 70 is brought into contact with the winding drum 3,
The spline shaft portion 32 of the spindle shaft 4 and the winding drum 3 may be fastened via the ring member 70 and the ratchet wheel 50.

Next, a modified embodiment in which the above embodiment is partially modified will be described. However, the same components as those in the above embodiment will be described with the same reference numerals.

1] Modified Embodiment 1—See FIG. 11 The seat belt retractor 1A is configured such that, in the fastening mechanism 8A, a female screw portion 81 formed on the winding drum 3A and a portion near the right end of the spindle shaft 4 rotate relative to each other. A ratchet wheel 50A is provided with a screwing mechanism 80 formed on a ratchet wheel 50A that is uncoupled, and has a female screw portion 82 screwed with a female screw portion 81. The ratchet wheel 50A and the winding drum 3A are brought into contact with each other, thereby Through the wheel 50A,
Spline shaft part 32 of spindle shaft 4 and winding drum 3
A.

A fitting hole 26A is formed in the center of the right flange 22 of the winding drum 3A.
A female screw 81 is formed on the peripheral surface of the gear A, and a guide portion 55A is formed integrally with the ratchet wheel 50A with a smaller diameter than the gear portion 53 and on the left side of the gear portion 53, and a male portion is formed on the left portion of the guide portion 55A. The screw portion 82 is formed, and the fitting hole 2 is formed.
The inner end surface of 6A and the left end surface of guide portion 55A can be brought into contact with each other.

According to the seat belt retractor 1A, substantially the same operation and effects as those of the above-described embodiment can be obtained, but the ring member 70 can be omitted as compared with the above-described embodiment, so that the structure is simplified and the assembling becomes advantageous. Manufacturing costs are also reduced. Since the spline shaft portion 32 of the spindle shaft 4 and the ratchet wheel 50 are relatively movable in the left-right direction, expansion and contraction of the spindle shaft 4 due to torsional deformation can be allowed.

2] Modified Embodiment 2—See FIG. 12 The seat belt retractor 1B is formed near the other end of the female screw 86 formed on the winding drum 3B and the spindle shaft 4B in the fastening mechanism 8B. A screw mechanism 85 having a male screw part 87 screwed to the female screw part 86.
The spindle shaft 4B and the ratchet wheel 50B are integrally formed, and the vicinity of the right end of the spindle shaft 4B is brought into contact with the winding drum 3B so that the vicinity of the right end of the spindle shaft 4B and the winding drum 3B are fastened. It is composed.

The right flange 22 of the winding drum 3B is formed with a fitting hole 26B at the center thereof.
B, a female screw 86 is formed on the peripheral surface of the spindle shaft 4B.
A guide portion 55B is integrally formed at the right end portion of the first portion, and a male screw portion 87 is formed at the left portion of the guide portion 55B.
The inner end surface of 6B and the left end surface of the guide portion 55B can contact each other. The ratchet wheel 50B is formed integrally with the spindle shaft 4B on the right side of the guide portion 55B.

According to the seat belt retractor 1B, substantially the same operation and effects as those of the above-described embodiment can be obtained, but the ring member 70 can be omitted as compared with the first alternative embodiment, and the spindle shaft 4B and the ratchet wheel 50B Are formed integrally, the structure is further simplified, the assembling is advantageous, and the manufacturing cost can be reduced.

3) In addition, as a structure in which one end of the spindle shaft and the winding drum are engaged with each other so as not to rotate relative to each other, the cap member 35 is omitted, and one end of the spindle shaft and the winding drum are directly engaged. Alternatively, one end of the spindle shaft and the winding drum may be engaged via another connecting member instead of the cap member 35.

4) In the emergency lock mechanism for locking the vicinity of the other end of the spindle shaft so as not to rotate, various emergency lock mechanisms other than the emergency lock mechanism 7 of the above-described embodiment can of course be applied. Also, various structures can be applied to the winding drum 3, the rotation urging mechanism 5, the forced winding mechanism 6, and the like.

The seat belt retractor according to the present invention is not limited to the one described in the above embodiment, and various modifications may be added without departing from the gist of the present invention to provide various types of seat belt retractors. Can be applied.

[0068]

According to the seat belt retractor of the first aspect, in the event of a vehicle emergency, the spindle shaft is twisted until the amount of torsional deformation rotation of one end of the spindle shaft with respect to the vicinity of the locked other end reaches a predetermined value. And the take-up drum is fastened to the take-up drum when the torsional deformation rotation amount reaches a predetermined value. Even when a very large load is applied to the vehicle, or when the vehicle repeatedly collides several times at once and the spindle shaft is repeatedly torsionally deformed, the kinetic energy of the occupant is absorbed and the spindle shaft is reliably prevented from breaking. Finally, since the occupant can be reliably restrained by the webbing, the occupant is reliably prevented from secondary collision with the steering wheel, the front window, etc., and the occupant is secured. be able to.

According to the seat belt retractor of the present invention, the winding drum, the spindle shaft, the emergency locking means, and the winding drum and one end of the spindle shaft are integrally formed by the tension applied to the webbing after the operation of the emergency locking means. The spindle shaft is allowed to torsionally deform until the amount of torsional deformation rotation of the one end of the spindle shaft with respect to the vicinity of the other end of the spindle shaft in the webbing pull-out direction reaches a predetermined value, and the torsional deformation rotation is performed. When the amount reaches a predetermined value, there is provided a fastening mechanism for fastening the vicinity of the other end of the spindle shaft and the take-up drum so that they cannot rotate relative to each other. Even when a load is applied or when the vehicle is hit several times at a time and the spindle shaft is repeatedly torsionally deformed, the kinetic energy of the occupant is absorbed and the spindle To reliably prevent passengers from breaking, and ultimately the occupant can be securely restrained by webbing, so that secondary collision of the occupant with the steering wheel, front window, etc. is reliably prevented, and occupant safety is ensured. Can be.

According to the seat belt retractor of the third aspect, the same effect as that of the first or second aspect is obtained, but the fastening mechanism is a female screw formed on the vicinity of the other end of the spindle shaft and one of the winding drums. And a male screw part formed on the other side and having a male screw part screwed to the female screw part, so that the structure of the fastening mechanism is simplified and the manufacturing cost is reduced, and the fastening mechanism allows the vehicle to be used in an emergency. Until the amount of torsional deformation rotation of the spindle shaft reaches a predetermined value, the winding drum can be relatively rotated with respect to the vicinity of the other end of the spindle shaft,
When the torsional deformation of the spindle shaft is allowed, and when the amount of rotation of the torsional deformation reaches a predetermined value, the female screw and the male screw of the screwing mechanism are screwed and fastened to the vicinity of the other end of the spindle shaft. The winding drum and the winding drum can be securely fastened so that they cannot rotate relative to each other.

According to the seat belt retractor of the fourth aspect, the same effect as that of the first or second aspect is obtained, but the fastening mechanism is an emergency locking means for locking the vicinity of the other end of the spindle shaft in a non-rotatable manner in a vehicle emergency. And a screwing mechanism having a female screw portion formed on one of the winding drum and a male screw portion formed on the other and screwed to the female screw portion, which constitutes a part of the The structure is simplified and the manufacturing cost is reduced, and the fastening mechanism
Until the torsional deformation rotation amount reaches a predetermined value, the winding drum can be relatively rotated with respect to a ratchet wheel integrally provided in the vicinity of the other end of the spindle shaft so as to be relatively non-rotatable. When the torsional deformation is allowed and the amount of rotation of the torsional deformation reaches a predetermined value, the female screw and the male screw of the screwing mechanism are screwed and fastened, and the other end near the spindle shaft and the winding drum Can be securely fastened so that relative rotation is impossible.

According to the seat belt retractor of the fifth aspect, the same effect as that of the third aspect is obtained, but the fastening mechanism makes the spindle shaft of the spindle shaft contact by bringing the vicinity of the other end of the spindle shaft into contact with the winding drum. Since the winding drum is fastened to the vicinity of the other end, when the amount of torsional deformation rotation reaches a predetermined value in the event of a vehicle emergency, the winding drum is brought into contact with the vicinity of the other end of the spindle shaft, The winding drum can be more securely fastened to the vicinity of the other end of the spindle shaft.

According to the seat belt retractor of the sixth aspect, the same effect as that of the fourth aspect can be obtained, but the fastening mechanism makes the ratchet wheel and the winding drum come into contact with each other so as to make contact with the vicinity of the other end of the spindle shaft. Since the take-up drum is fastened, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ratchet wheel and the take-up drum are brought into contact with each other, and the other end of the spindle shaft is connected via the ratchet wheel. The vicinity portion and the winding drum can be more securely fastened.

According to the seat belt retractor of the seventh aspect, the same effect as that of the first or second aspect is obtained, but the fastening mechanism is externally fitted to the vicinity of the other end of the spindle shaft and is relatively opposed to the winding drum. Since the ring member is non-rotatably fitted, the ring member and the winding drum can be relatively rotated with respect to the spindle shaft until the torsional deformation rotation amount of the spindle shaft reaches a predetermined value in the event of a vehicle emergency. Then, the torsional deformation of the spindle shaft is allowed, and when the amount of rotation of the torsional deformation reaches a predetermined value, the ring member is screwed and fastened to the vicinity of the other end of the spindle shaft, and the spindle member is connected via the ring member. The vicinity of the other end of the shaft and the winding drum can be securely fastened to each other so that they cannot rotate relative to each other.

According to the seat belt retractor of the eighth aspect, the same effect as that of the first or second aspect is obtained, but the fastening mechanism locks the vicinity of the other end of the spindle shaft non-rotatably in a vehicle emergency. Since the ring member is externally screwed onto the ratchet wheel forming a part of the shaft member and is internally fitted on the winding drum so as to be relatively non-rotatable, the amount of rotation of the torsional deformation of the spindle shaft during a vehicle emergency is a predetermined value. Until the ring member is rotatable relative to the ratchet wheel together with the winding drum to allow torsional deformation of the spindle shaft, and when the torsional deformation rotation amount reaches a predetermined value, the ring member is rotated. By screwing it to the ratchet wheel, the other end of the spindle shaft and the take-up drum can be securely fastened to the take-up drum via the ring member and the ratchet wheel. .

According to the seat belt retractor of the ninth aspect, the same effect as that of the seventh or eighth aspect is obtained, but the ring member is fitted inside the winding drum so as to be relatively movable in the axial direction thereof. Therefore, when the ring member is relatively rotated with respect to the spindle shaft or the ratchet wheel, the movement of the ring member in the axial direction can be allowed, and expansion and contraction of the spindle shaft due to torsional deformation can be allowed. .

According to the seat belt retractor of the tenth aspect, the same effect as that of the seventh aspect is obtained, but the fastening mechanism is
Since the ring member is brought into contact with the winding drum to fasten the winding drum to the vicinity of the other end of the spindle shaft, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ring member and By bringing the take-up drum into contact with the take-up drum, the take-up drum can be more securely fastened to the vicinity of the other end of the spindle shaft via the ring member.

According to the seat belt retractor of the eleventh aspect, the same effect as that of the eighth aspect is obtained, but the fastening mechanism is
By bringing the ring member into contact with the ratchet wheel to fasten the winding drum to the vicinity of the other end of the spindle shaft, when the torsional deformation rotation amount reaches a predetermined value in a vehicle emergency, the ring member and the ratchet By contacting the wheel, the vicinity of the other end of the spindle shaft and the winding drum can be more securely fastened via the ring member and the ratchet wheel.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a seat belt retractor according to an embodiment of the present invention.

FIG. 2 is a perspective view from the upper left side of the seat belt retractor.

FIG. 3 is a perspective view from the upper right side of the seat belt retractor.

FIG. 4 is a perspective view of a main part of the seat belt retractor.

FIG. 5 is a sectional view of a main part of the seat belt retractor.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 5;

FIG. 8 is a sectional view of a main part of the seat belt retractor.

FIG. 9 is a sectional view of a main part of the seat belt retractor.

FIG. 10 is a diagram showing load characteristics acting on webbing.

FIG. 11 is a cross-sectional view of a main part of a seat belt retractor according to the first embodiment.

FIG. 12 is a sectional view of a main part of a seat belt retractor according to a second embodiment.

[Explanation of symbols]

 W Webbing 1, 1A, 1B Seat belt retractor 3, 3A, 3B Winding drum 4, 4B Spindle shaft 7 Emergency lock mechanism 8, 8A, 8B Fastening mechanism 30 Torsion bar 50, 50A, 50B Ratchet wheel 70 Ring member 75, 80,85 screw mechanism

Claims (11)

[Claims] 1. A winding drum for winding a webbing, and a spindle shaft having one end engaged with the winding drum so as to be relatively non-rotatable and functioning as a torsion bar. In a seat belt retractor configured to perform energy absorption, in the event of a vehicle emergency, torsional deformation of the spindle shaft is permitted until the amount of torsional deformation rotation of one end of the spindle shaft with respect to the vicinity of the other end reaches a predetermined value, and A seat belt retractor comprising a fastening mechanism for fastening a portion near the other end of the spindle shaft and the winding drum so that the winding drum cannot rotate relative to each other when the amount of torsional deformation rotation reaches a predetermined value. 2. A winding belt for winding webbing in a seat belt retractor that absorbs energy through torsional deformation of a torsion bar in a vehicle emergency, and is disposed so as to pass through the winding drum. A spindle shaft having a torsion bar portion which is engaged with the winding drum at one end so as to be relatively non-rotatable; emergency locking means for non-rotatably locking the other end of the spindle shaft in the event of a vehicle emergency; The winding drum and one end of the spindle shaft rotate integrally due to the tension applied to the webbing after the operation of the means, and the amount of twist deformation rotation in the webbing pull-out direction with respect to the vicinity of the other end of one end of the spindle shaft becomes a predetermined value. Until the torsional deformation of the spindle shaft reaches a predetermined value. Seat belt retractor characterized by comprising a fastening mechanism for fastening the parts and the winding drum in a relatively non-rotatable manner, a. 3. The screwing mechanism according to claim 1, wherein the fastening mechanism includes a female screw portion formed on one of a winding drum and a male screw portion formed on the other of the vicinity of the other end of the spindle shaft and screwed to the female screw portion. The seat belt retractor according to claim 1 or 2, further comprising a mechanism. 4. A female screw portion formed on one of a ratchet wheel and a take-up drum which constitutes a part of an emergency locking means for locking the vicinity of the other end of the spindle shaft in a non-rotatable manner in a vehicle emergency. The seat belt retractor according to claim 1 or 2, further comprising a screwing mechanism having a male screw part formed on the other side and screwed into the female screw part. 5. The fastening mechanism according to claim 1, wherein the winding drum is fastened to the vicinity of the other end of the spindle shaft by bringing the vicinity of the other end of the spindle shaft into contact with the winding drum. 4. The seat belt retractor according to 3. 6. The sheet according to claim 4, wherein the fastening mechanism fastens the winding drum with the vicinity of the other end of the spindle shaft by bringing the ratchet wheel into contact with the winding drum. Belt retractor. 7. The fastening mechanism according to claim 1, further comprising a ring member externally fitted to a portion near the other end of the spindle shaft and internally fitted to the winding drum so as to be relatively non-rotatable. 3. The seat belt retractor according to 2. 8. The fastening mechanism is externally threadedly engaged with a ratchet wheel which constitutes a part of an emergency locking means for non-rotatably locking the vicinity of the other end of the spindle shaft in the event of a vehicle emergency, and is relatively rotated with respect to the winding drum. The seatbelt retractor according to claim 1, further comprising a ring member that is fitted in an impossible manner. 9. The seat belt retractor according to claim 7, wherein the ring member is internally fitted to the winding drum so as to be relatively movable in the axial direction thereof. 10. The seat belt according to claim 7, wherein the fastening mechanism fastens the winding drum to the vicinity of the other end of the spindle shaft by bringing a ring member into contact with the winding drum. Retractor. 11. The seat belt retractor according to claim 8, wherein the fastening mechanism fastens the take-up drum to the vicinity of the other end of the spindle shaft by bringing a ring member into contact with a ratchet wheel. .